Honestly, as much as I like forewarning, I think all that would really happen if it's announced in the forums is that the outcry and complaining would happen in a centralized location and be more visible and probably feed itself - and be something that the course designers, judges, and administration at NADAC would have to experience.
Maybe announcements at judges attending trials a month or so in advance or something? but putting it on line just centralizes it in a way that may not be helpful. But that's just initial response to the idea, based on seeing forum reactions to changes in the past.